I have a fresh install of 13.10 and my networking works fine (cable model cloud router) via the standard network manager applet.

I'm trying to setup my box to a use static IP instead of dhcp and I'm trying to use your guide:
https://help.ubuntu.com/13.10/serverguide/network-configuration.html#ip-addressing

Basically, the settings via the networking applet seem to be conflicting with what I see on the command line.

a) The ifconfig -a shows eth0 with the inet address assigned via dhcp.

ifconfig -a



eth0      Link encap:Ethernet  HWaddr 44:87:fc:97:ed:24  

      inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0

      inet6 addr: fe80::4687:fcff:fe97:ed24/64 Scope:Link

      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

      RX packets:61170 errors:0 dropped:0 overruns:0 frame:0

      TX packets:41321 errors:0 dropped:0 overruns:0 carrier:0

      collisions:0 txqueuelen:1000 

      RX bytes:79517729 (79.5 MB)  TX bytes:4735861 (4.7 MB)



lo        Link encap:Local Loopback  

      inet addr:127.0.0.1  Mask:255.0.0.0



.....

.....

b) However, the interfaces file does not have even eth0 defined.

cat /etc/network/interfaces

auto lo

iface lo inet loopback

c) I could not even do:

sudo ifdown eth0

ifdown: interface eth0 not configured

How is this possible or what am I basically missing ?

Will the steps in the link above for configuring a static IP work ?

Thanks,

Dinshaw